Tough, high strain to failure materials with good stiffness (modulus) are needed by all segments of industry and commerce, but the automotive and aerospace industries are particularly in need of such materials that are also inexpensive and/or lightweight. Traditional approaches have used exotic polymers (expensive) or ceramic fiber reinforced composites (heavy) to achieve these goals.
The key to achieving high levels of toughness in combination with high modulus is to generate immiscible blends of materials that individually provide the necessary properties. The difficulty in achieving this is that most immiscible blends of tough [e.g. HDPE] and stiff [e.g. PMMA] polymers have miserable properties.